Institute of Electrical and Electronics Engineers (IEEE) 802.11ad is known as a wireless communication standard for performing high-speed data transmission through a millimeter-waveband (60 GHz), which has a relatively narrow communication range where radio waves travel in a highly straight line.
Further, there is a communication network known in the art that broadcasts data contents from a transmitter-node to multiple receiver-nodes via a relaying receiver-node (see PTL 1, for example).